PROBLEM TO BE SOLVED: To provide a material having activities for inhibiting prostaglandin production, and useful for antiinflammatory or amelioration of dermal inflammatory symptom.SOLUTION: The prostaglandin E2 production inhibitor includes Alisma plantago-aquatica var.orientale or an extract thereof as an active ingredient. Preferably, the extract is the one extracted with an aqueous solution of ethanol in the prostaglandin E2 production inhibitor.COPYRIGHT: (C)2012,JPO&INPIT【課題】プロスタグランジン産生抑制作用を有し、抗炎症又は皮膚炎症性症状の改善のために有用な素材の提供。【解決手段】サジオモダカ又はその抽出物を有効成分とするプロスタグランジンE2産生抑制剤。【選択図】なし